Thursday, March 17, 2011

Haiti Cholera Epidemic Could Sicken 779,000 This Year

The cholera epidemic in Haiti this year will be far worse than the 400,000 cases predicted by the United Nations, new study findings indicate.

There could be nearly twice as many cases of the potentially deadly diarrheal disease -- an estimated 779,000 -- between March and November of this year, according to researchers at the University of California, San Francisco and Harvard Medical School.

The discrepancy is important because U.N. projections determine the allocation of resources to fight the disease, said the authors of the study, published March 16 in The Lancet.

"The epidemic is not likely to be short-term," Dr. Sanjay Basu, a UCSF medical resident, said in a university news release. "It is going to be larger than predicted in terms of sheer numbers and will last far longer than the initial projections."

The cholera epidemic erupted in Haiti after last year's devastating earthquake. Cholera -- spread from person-to-person through contaminated food and water -- can be deadly if untreated. In most cases, treatment for the diarrhea caused by the disease involves rehydration with salty liquids.

Late last year, the U.N. projected that a total of 400,000 people in Haiti would eventually become infected with cholera. They reached that total by assuming that cholera would infect 2 to 4 percent of Haiti's population of 10 million. But the U.N. estimate did not take into account existing disease trends, or factors such as where water was contaminated, how the disease is transmitted, or human immunity to cholera, Basu said.

Basu and colleague Dr. Jason Andrews, a fellow at the Massachusetts General Hospital and Harvard Medical School, used data from Haiti's Ministry of Health and other sources to develop a more sophisticated model of the spread of cholera in several provinces in Haiti.

That led to their predictions of 779,000 cases of cholera and about 11,100 deaths in the next eight months.

The researchers also examined the impact of making clean water more available and the use of vaccines or antibiotics. They found that a 1 percent decrease in the number of people who drink contaminated water would prevent more than 100,000 cases of cholera and about 1,500 deaths this year.

In addition, simply offering vaccination to an estimated 10 percent of the population could save about 900 lives, and more widespread use of antibiotics could prevent 9,000 cases of cholera and about 1,300 deaths.